evanmiller/erlydtl — pull request #95 by dgulino (2013-10-24 20:44:42+00:00)
Title: New time format string 'o' – the ISO 8601 year number

One of two new format strings in Django 1.4:
https://docs.djangoproject.com/en/dev/releases/1.4/#two-new-date-format-strings